1. Field of the Invention
This invention pertains to advertising, and more particularly to apparatus that enhances the appearance of alpha-numeric displays.
2. Description of the Prior Art
Various types of equipment have been developed to display commercial advertising and other promotional messages. For example, display panels that hold interchangeable characters such as numerals and alphabet letters are well known and in widespread use. Examples of prior display panels may be seen in U.S. Pat. Nos. 4,237,637; 4,265,040; 5,257,472; 5,357,701; and 5,367,800.
In some instances, the display panels are translucent or transparent such that a source of illumination can backlight the characters on the panel. U.S. Pat. Nos. 4,367,604 and 5,588,238 show backlit menu boards.
U.S. Pat. No. 5,542,202 and Des. 354,313 show representative plates that include characters for display. The plate of the U.S. Pat. No. 5,542,202 patent is especially useful with backlit display panels.
Despite the large variety of display panels, alpha-numeric characters, and character plates that are presently available, they are limited in the size and variety of graphic arts that can be handled. U.S. Pat. No. 4,367,604 shows graphic picture units, but they must be custom made to suit a particular display panel. U.S. Pat. No. 5,588,238 shows pictorial assemblies that are sandwiched between transparent window panels. The pictorial assemblies must thus be of a specific size and shape. In addition, the design of the U.S. Pat. No. 5,588,238 patent is such that it is difficult to change or rearrange the pictorial assembly after it has been created.
A further disadvantage of prior display equipment is that the numeral and alphabet letter plates are limited to use with specific tracks of a display panel. That is, the plates are all of the same height so as to fit within the tracks. Accordingly, variations in character heights in a particular track of a display panel are usually not possible.
Thus, a need exists for improvements in the way graphic materials are displayed on display panels.